Skip to Content
Merck
  • S-ketamine versus racemic ketamine in dogs: their relative potency as induction agents.

S-ketamine versus racemic ketamine in dogs: their relative potency as induction agents.

Veterinary anaesthesia and analgesia (2014-07-22)
Daniela Casoni, Claudia Spadavecchia, Chiara Adami
ABSTRACT

To determine the potency ratio between S-ketamine and racemic ketamine as inductive agents for achieving tracheal intubation in dogs. Prospective, randomized, 'blinded', clinical trial conducted in two consecutive phases. 112 client-owned dogs (ASA I or II). All animals were premedicated with intramuscular acepromazine (0.02 mg kg(-1)) and methadone (0.2 mg kg(-1)). In phase 1, midazolam (0.2 mg kg(-1)) with either 3 mg kg(-1) of racemic ketamine (group K) or 1.5 mg kg(-1) of S-ketamine (group S) was administered IV, for induction of anaesthesia and intubation. Up to two additional doses of racemic (1.5 mg kg(-1)) or S-ketamine (0.75 mg kg(-1)) were administered if required. In phase 2, midazolam (0.2 mg kg(-1)) with 1 mg kg(-1) of either racemic ketamine (group K) or S-ketamine (group S) was injected and followed by a continuous infusion (1 mg kg minute(-1)) of each respective drug. Differences between groups were statistically analyzed via t-test, Fisher exact test and ANOVA for repeated measures. Demographics and quality and duration of premedication, induction and intubation were comparable among groups. During phase 1 it was possible to achieve tracheal intubation after a single dose in more dogs in group K (n = 25) than in group S (n = 16) (p = 0.046). A dose of 3 mg kg(-1) S-ketamine allowed tracheal intubation in the same number of dogs as 4.5 mg kg(-1) of racemic ketamine. The estimated potency ratio was 1.5:1. During phase 2, the total dose (mean ± SD) of S-ketamine (4.02 ±1.56 mg kg(-1)) and racemic ketamine (4.01 ± 1.42) required for tracheal intubation was similar. Racemic and S-ketamine provide a similar quality of anaesthetic induction and intubation. S-ketamine is not twice as potent as racemic ketamine and, if infused, the potency ratio is 1:1.

MATERIALS
Product Number
Brand
Product Description

Sigma-Aldrich
Lidocaine, powder
SKU
Pack Size
Availability
Price
Quantity
Sigma-Aldrich
Lidocaine, analytical standard
SKU
Pack Size
Availability
Price
Quantity
Supelco
Lidocaine, Pharmaceutical Secondary Standard; Certified Reference Material
SKU
Pack Size
Availability
Price
Quantity
Lidocaine, European Pharmacopoeia (EP) Reference Standard
SKU
Pack Size
Availability
Price
Quantity
USP
Lidocaine, United States Pharmacopeia (USP) Reference Standard
SKU
Pack Size
Availability
Price
Quantity